What are your tips on FaceTimeing a girl?

So I met this girl and I'm gonna FaceTime her tonight. If you don't know what FaceTime is, it's basically like Skype or any other facecam meeting site, but it's for people who have iPhones. Anyway, I met her yesterday and I asked if we can FaceTime tonight and she said yes, I don't want to look weird or ridiculous or completely blank out and not know what to say so what are your tips on facetiming girls?